UPPERVILLE, VA. — Before she went to bed two Sundays ago, Sarah Libbey Greenhalgh popped a final message up on her Facebook page. She said she was going to sleep with her windows open and would rest peacefully as long as “crazy boy left me alone.”

The next morning, an off-duty firefighter spotted smoke rising from the farm cottage where she lived alone. As firefighters doused the flames, they found Greenhalgh, 48, dead in a back bedroom.

Authorities soon determined that the popular journalist, photographer and daughter of a family prominent on both sides of the Potomac had been slain, although they aren’t saying how she died.

In a search for her killer, police have sought the identity of the person in her Facebook post and other men she met through online dating sites. They’ve probed her stories at the Winchester Star newspaper and they’ve stopped drivers on the street near her rented home, looking for anyone who might have seen something.

But people in this picturesque village that sits amid green pastures remain shocked. Upperville rarely sees serious crime — let alone a homicide. And the killing has taken a name storied in equestrian circles and among the country estates that dot the area. Greenhalgh, who grew up in Potomac, was also the daughter of a once-prominent Montgomery County politician.

The slain Winchester Star reporter Sarah Libbey Greenhalgh. This photo was taken in the '90s. (Courtesy of Douglas Lees/COURTESY OF DOUGLAS LEES)

The Fauquier County Sheriff’s Office has not named a suspect in the case, and authorities said they are talking to multiple “persons of interest.”

Greenhalgh’s family and friends remember her as a bold, dynamic and blunt woman who loved horses and travel and was deeply dedicated to her work. One friend joked that there should have been a ripple “in the force” with Greenhalgh’s death because she “had that much presence.” Her Facebook page and online forums have filled with remembrances as word of her death has spread.

Kate Langton, Greenhalgh’s sister, was careful to say that she has no idea who killed her sibling, but said Greenhalgh had another side, too: She was not afraid to involve herself in messy relationships or situations.

“She didn’t shy away from the complicated,” Langton said. “She would look the dark right in the face. Unfortunately, it seems like it started looking back at her.”

One of those relationships was with the person from the Facebook post, Langton said, a man whom Greenhalgh dated on and off in the months before her death. He was depressed and had been going through a divorce, Langton said. Still, she said she didn’t think he could have killed her sister.

On the day before her body was found, whatever darkness befell Greenhalgh seemed far away, Langton said. She and her sister chatted happily that Sunday morning, and Greenhalgh had a routine visit with acquaintances later that evening, police said. Nothing seemed amiss.

In fact, Langton said her sister was in a good place in life. Greenhalgh had plunged into her job as the Frederick County government reporter at the Star, after being out of work for more than a year.

It was about 8 a.m. on July 9 when the off-duty firefighter reported the fire at Greenhalgh’s home. The Greenhalgh case would become Fauquier County’s first homicide of 2012.

The next day police served a search warrant on an apartment in Gainesville, where the Star reported that the man mentioned in Greenhalgh’s last Facebook post is thought to have lived. A neighbor of the man reported seeing him and Greenhalgh arguing in the parking lot on Sunday.

“They were cursing at each other,” said the neighbor, who declined to be identified.

In the search warrant filed in Prince William County court, police said they were looking for trace evidence of accelerant, DNA evidence, fibers, cellphones and firearms, among other things. They removed a T-shirt, BlackBerry and shredder waste from the apartment, according to the court filing.

Langton said Greenhalgh wanted to take the man to a family wedding she attended in Berryville the Saturday before her body was found. She said she thought Greenhalgh’s reference to him as “crazy boy” was a term of affection, not a warning.

Police said the man is cooperating with the investigation. The Post is not identifying him because he has not been named a suspect in the case. It wasn’t Greenhalgh’s only rocky relationship. Friends said she had trouble with another ex-boyfriend in the past.

Detectives are also probing whether something she wrote might have angered someone. Investigators interviewed staff at the Star and removed Greenhalgh’s work computer and some files from the newsroom last week, police said. And detectives are talking with a handful of people connected to stories Greenhalgh wrote.

Star staff asked police to take a particularly close look at one story Greenhalgh had worked on, but both police and a Star editor declined to discuss its nature. However, managing editor Maria Hileman said she didn’t think the areas Greenhalgh covered — the Board of Supervisors, sewer issues and more — would put her in harm’s way.

The case has put the Star in an awkward position: Going from reporting on the news to being a part of it.

“I do feel as the manager here my emotional reaction and approach to the story is slightly different,” Hileman said. “Our first and highest priority is to Sarah and her memory. We have to be very careful in our own pursuit of the investigation.”

Hileman said that has meant working closely with the police and, in one instance, holding back publishing information about a search warrant, so police could serve it unimpeded.

Hileman said the staff has left Greenhalgh’s desk untouched, except for placing a vase of flowers on it in remembrance of her. Hileman said she was effervescent and a tenacious reporter.

Greenhalgh may be best remembered for her equestrian photography and reporting. She freelanced for The Washington Post, the Chronicle of the Horse and other publications. Her passion was a lifetime in the making, Greenhalgh’s mother said.

Sarah Lee Greenhalgh took her daughter riding during her youth and she played with a herd of ponies her mother had rescued. The Greenhalgh family, which once owned the palatial Springsbury Farm estate in Berryville, Va., has been prominent in Virginia’s horse country for generations. An aunt was the master of the Blue Ridge Hunt, a fox-hunting event, for many years.

William Greenhalgh, Sarah Libbey Greenhalgh’s father, was the president of the Montgomery County Board of Supervisors in the 1960s and a former associate dean of the Georgetown University Law School. Greenhalgh’s grandfather made a fortune founding the successful Owens Illinois glassworks, which became part of Owens Corning. William Greenhalgh died in 1994.

Sarah Lee Greenhalgh, who lives in Poolesville, said her daughter’s death seemed unreal — almost a movie.

“It is beyond my ability to understand,” Greenhalgh said. “I never knew someone that something so horrible has happened to . . . I can’t comprehend what happened. I’m overcome with grief.”